In recent years, flip-chip bonding techniques have increasingly been used to connect (bond) integrated circuit (IC) chips to interconnection substrates and to package substrates. In flip-chip bonding an IC chip component to an interconnection component such as ceramic interconnection substrate, a plurality (e.g., an array) of solder balls (also called “solder bumps”) is formed on a face of a component, typically the IC chip component, and the bumped component is brought into a face-to-face relationship with the other component. The two components are then heated (such as in a furnace) to reflow (heat, then allow to cool) the solder bumps, thereby making electrical connections between respective terminals of the two components.
A need for ever finer pitch arrays of solder balls has accompanied an increase in the circuit density of IC chips and multi-chip modules. For example, an IC chip to be flip-chip connected to an interconnection substrate may require an array of 4 mil (100 μm) diameter solder balls disposed at an 8 mil (200 μm) pitch.